A conventional terminal apparatus such as a cellular phone or the like having a touch panel is capable of changing a key layout of a standby screen by user's operation and displaying the key layout in accordance with conditions in passive situations such as reception of an e-mail, reception of a voice call and the likes. For example, it is possible to arrange shortcut keys such as an e-mail button, an address button, a calculator button and the likes in addition to a normal key layout on the standby screen, and also to display the key layout in accordance with situations such as an in-box button or an answer button when receiving an e-mail or a voice call, respectively.
As the conventional art, there is a display control apparatus designed so that each button or each touch panel has an input function even when the function is not displayed on the display (see Patent Document 1). The touch panel of the conventional art is shown in FIG. 7. There are touch panel areas P1 to P6 and display buttons D1 to D6 corresponding to the areas, respectively. For example, when a user presses each of the touch panel areas P1 to P6 on a navigation screen, each of the display buttons D1 to D6 performs a corresponding function. Then, when the display is changed from the navigation screen to a TV screen, the display buttons D1 to D6 disappear from the screen so as to display the TV screen. Although the display buttons D1 to D6 are not displayed, navigation functions operate when the user presses the touch panel areas P1 to P6.    Patent Document 1: Japanese Utility Model Application Laid-Open No. 7-6828